This invention relates to an exposure apparatus such as a semiconductor manufacturing apparatus for manufacturing semiconductor devices such as LSI and VLSI devices, as well as a device manufacturing method that employs this exposure apparatus.
In order to process separate lots in a semiconductor device manufacturing operation quickly and efficiently, a plurality of semiconductor exposure apparatuses used in a lithographic process are typically placed under the overall control of a host computer or personal computer hierarchically superior to the computer on the side of each exposure apparatus. Ordinarily, a command to start the exposure processing is issued after specific parameters for exposure (a "job") necessary to process a certain lot are selected from a database in which operating parameters have been stored.
Further, in order to raise the availability rate of each exposure apparatus at a semiconductor plant and achieve unmanned operation in a clean room to cope with the automation of semiconductor device manufacture, there is a tendency to place coating and developing equipment used in processes upstream and downstream of each exposure apparatus inline and perform overall control by a host computer or personal computer.
When exposure is carried out, often one carrier (25 wafers) is treated as one lot. If volume of production is low and there are a wide variety of products made, the job used or the reticle used usually differs from one lot to the next. However, in a case where volume of production is high and there are a narrow variety of products made, it is possible that the same job and reticle will be used for two or three lots in succession.
In order to automate the manufacturing operation, raise the availability rate of each exposure apparatus, and perform operations efficiently in these circumstances, the changeover from one lot to another must be executed at the highest speed practicable. The prior art is such that even in a case where two or three successive lots are processed by the same job and reticle, a job selected from a database is transferred to the exposure apparatus proper and calibration processing is always executed from one lot to the next.
In accordance with the aforementioned example of the prior art, however, despite the fact that the same job and reticle are used for two or three lots in succession, re-transfer of the job and re-measurement for calibration are performed from one lot to the next. As a consequence, the real availability rate of the exposure apparatus declines and time is wasted at the changeover between lots.